Shows construction of Hoover Dam from the upstream side. Buildings and trucks are visible on the cofferdam. One of the portals to the diversion tunnels can be seen at lower left. The intake towers are rising...

Shows a panoramic view of the Hoover Dam site in Black Canyon. There are trucks and buildings visible on the floor of the canyon. One of the portals to the diversion tunnels is visible. The concrete pouring...

Shows the construction of Hoover Dam from the downstream side. The power houses are nearly completed and one of the portals to the diversion tunnels is visible. There are trucks and buildings on the floor of the canyon....

View of Hoover Dam during construction, looking downstream. The cooling tower and refrigeration plant are visible; also shows concrete forms, high scaling equipment, and various consruction materials and trucks. There is a man in the lower left-hand corner...

View taken high above Hoover Dam construction site showing the forms for poruing the concrete. There are trucks, buildings, a railroad, and roads visible. The Colorado River can be seen above the site. Other construction equipment shown includes...

View of the Hoover Dam construction site from high above showing forms for the poring of the concrete, looking downstream. There are trucks, a train along the canyon wall, and buildings in the picture. Construction equipment includes...

View of construction on the upstream face of Hoover Dam. Construction equipment, scaffolding and concrete pouring forms are seen on and around the dam wall. Temporary stairs are seen attached to the wall of Black Canyon on the...

View of construction on the upstream face of Hoover Dam in Black Canyon. Scaffolding, concrete pouring forms and other construction equipment are seen around the site. Temporary buildings and trucks are seen in the foreground.

View of construction of the foundations of the Arizona power house in the Colorado River bed in Black Canyon. Concrete pouring forms stand in the river bed and other construction equipment can be seen. Construction workers can be seen at...

View of construction of the Arizona power house at the dam site. Hoisting equipment, cables, trucks and construction workers can be seen. Various buildings and structures are pictured as well as roads and concrete pouring forms.

View of Hoover Dam and power house under construction. Buildings and structures, concrete pouring forms, cables, and a crane can be seen. Some construction workers and trucks are also pictured. Above the dam part of an intake...

General view of the construction of Hoover Dam, looking upstream. The power houses are being built in this phase. A cableway spans the canyon carrying a tram across. There are several buildings, construction workers, and trucks visible....

Shows the reinforcing framework for the Arizona power house and the locations for the turbine rooms, front room galleries, and penstocks. Some buildings, trucks, tunnel openings, and construction workers are visible.

Shows Hoover Dam construction from the top of the dam looking down. The power house, valve houses, and lower portals of the diversion tunnels are visible. Various buildings and trucks are also shown. The Colorado River is...

View of excavation and construction at the Hoover Dam switchyard. Note the Boulder Dam highway in the back (now U.S. 93). Power shovels, trucks, and buildings are visible, with the mountains in the background.

View looking upstream toward Hoover Dam. Alos shows the entrance to a tunnel and the powerhouses under construction. Trucks, cables, a cableway with trams, and other construction equipment can be seen.

View of construction on roads around the completed Arizona spillway, looking downstream on the Colorado River in Black Canyon. Curbs and guard rails are being installed. A dragline, two dump trucks and a temporary building are seen near the spillway....

View of construction on the Nevada power house from the downstream cofferdam. Concrete pouring forms and steel framework stand on top of the power house foundation. The dam face can be seen in the upper right. Temporary buildings, construction...

View of construction on the Nevada and Arizona power houses, taken from the valve house catwalk in the lower cofferdam. The dam face is seen in the background. Concrete pouring forms are visible on the power houses. Temporary buildings, construction...

View of the Hoover Dam construction site in Black Canyon, showing the nearly-completed dam face and construction on the power houses in the lower cofferdam. Concrete pouring forms are seen on the tops of the power houses. Temporary buildings,...

Construction on the Nevada power house. Concrete pouring forms are seen on top of the structure's foundation. A portion of the dam face is seen in the background. Temporary buildings, motor vehicles, electric draglines and construction equipment are seen on...

View of the Hoover Dam construction site in Black Canyon, showing the nearly-completed dam face and construction on the power houses in the lower cofferdam. Concrete pouring forms are seen on the tops of the power houses. Temporary buildings, construction...

View of the Hoover Dam construction site from downstream on the Nevada side. Construction on the intake towers nears completion behind the dam face. Scaffolding is still present on the dam face and cables run overhead. Temporary buildings are...

Shows the construction of Hoover Dam. One of the portals of the diversion tunnels is visible. Dynamite blasting is taking place in the canyon and trucks and various construction buildings are visible on the cofferdam. Also shows some...

"Down stream from Observation Point. Buildings on the right side are water sedimentation plants. Water treated for Boulder City. Left side is Arizona side of River." [hand-written inscription on back of photo] This photo was taken high...

This postcard shows the construction of Hoover Dam in four different stages. All views were taken from the same point looking upstream. The first image shows Black Canyon and the Colorado River at the very beginning of construction...

"First load of muck used in coffer dam [sic]. Looking at Arizona portals #3 & #4. Water now flowing thru these." (hand-written inscription on back of photo) Shows a dump truck dumping the muck and construction...

Panoramic view of the Hoover Dam construction site. One of the lower portals to a division tunnel can be seen. Buildings, trucks, and the cofferdam are also visible. A portion of the Colorado River is...

Shows construction at the lower portal of Hoover Dam. Part of the bridge is visible as are trucks, buildings, and construction workers. Part of the Colorado River is visible and also the wall of Black Canyon.

Shows the concrete pouring forms for the base of the dam. The upper cofferdam is in the background. Cableways, buildings, construction workers and trucks are visible. A railroad track runs along the side of the wall of Black Canyon.

Shows the head tower hoist house and permanent cableway. Cars and trucks are visible on the road across the dam as well as next to the hoist house. A transmission tower can be seen and construction workers are...

"Head tower hoist house and anchorage of permanent 150 ton cableway at Boulder Dam runs from upper end of hi[gh]mix gulch." (handwritten inscription on back of photo) Construction workers, trucks, and buildings are also visible.

Panoramic view of Black Canyon and Hoover Dam under construction. Two of the portals to the diversion tunnels are visible. The face of the dam is nearing completion and the concrete pouring forms can be seen. Part...

Aerial view of Hoover Dam, Black Canyon, and the Colordo River during the construction of the dam. Two portals of the diversion tunnels are visible. There are trucks and buildings on the cofferdam. The face of the...

View of the Hoover Dam construction site, looking upstream on the Colorado River in Black Canyon. The partially finished dam face can be seen on the right, with concrete pouring forms and other construction equipment. Construction of the Nevada power...

View of the Hoover Dam construction site, looking upstream on the Colorado River in Black Canyon. The partially finished dam face can be seen on the left, with concrete pouring forms and other construction equipment. Construction of the Arizona power...

This view, taken from the Nevada side of the canyon, shows the lower cofferdam being excavated. Trucks, buildings, , and construction roads are visible. The Colorado River can be seen below the site. There is a temporary...